Self-calibration methods and structures for pipelined analog-to-digital converters

Abstract

Self-calibration methods and structures are provided for pipelined ADCs which can be realized without requiring external measuring instruments or calibrators, without requiring major changes in pipeline structure and which can be rapidly obtained with stored calibration processes. In method embodiments, each of selected converter stages are calibrated by using succeeding stages as sub-ADCs which measure gain error at a transition step in a selected stage's residue transfer characteristic and saves the gain error as a calibration constant C for that stage. After a first calibration constant C has been obtained, the process is successively repeated for preceding converter stages except that previously-obtained calibration constants are multiplied by their respective stage's digital input signals D to obtain weighted calibration constants C which are included in measured gain errors to thereby obtain preceding calibration constants C .